from Wikipedia:
RB30
Three models of 3.0 L RB30 were produced:
* RB30S - carbureted single-cam
* RB30E - fuel-injected single-cam (114 kW @ 5200 rpm, 247 N·m (25.2 kgf·m) @ 3600 rpm)
* RB30E R31 Skyline - fuel-injected single-cam (117 kW @ 5200 rpm, 252 N·m (25.2 kgf·m) @ 3600 rpm)
* RB30ET VL Commodore - fuel-injected single-cam turbo (150 kW @ 5600 rpm, 296 N·m @ 3200 rpm)
This motor was produced because the Holden 202 (3.3 L) powering the Holden Commodore could no longer satisfy emissions requirements, and with all new cars required to run on unleaded petrol by 1986, a quick replacement was needed. Nissan Motor Co. sold the RB30E to Holden for the VL Commodore. The RB30E in the VL suffered from cylinder head cracking due to the radiator being fitted lower in the engine bay, causing air locks in the cylinder head. This was not as severe in R31 Skyline as the radiator is mounted higher. The engine proved to be very reliable apart from this issue. The RB30S was found in some Middle Eastern R31 Skylines and in some Nissan Patrols. The RB30E was found in R31 Skylines and VL Commodores in Australia as well as in South African R31 Skylines (with 126 kW @ 5000 rpm and 260 Nm @ 3500 rpm)
The turbocharged RB30ET (producing 150 kW) was found only in the VL Commodore (available in all Calais) and consisted of a lower compression RB30E bottom end, more powerful oil pump, T3 Garrett turbocharger, 250 cc injectors and a different intake manifold. The motor itself is still popular today (albeit in highly modified form) on the Australian Drag Racing circuit.
Nissan Special Vehicles Division Australia produced two limited models of R31 Skylines, the GTS1 and GTS2. These contained slightly more powerful RB30E engines, containing lumpier cams and better flowing exhausts.
* GTS1 RB30E - injected single-cam (130 kW @ 5500 rpm, 255 Nm (26.0 kgf·m) @ 3500 rpm) - special cam profile, special exhaust[6]
* GTS2 RB30E - injected single-cam (140 kW @ 5600 rpm, 270 N·m (27.5 kgf·m) @ 4400 rpm) - special cam profile, special exhaust, piggy back computer, valve porting[7]
RB30DE
These rare engines were used in the Tommy Kaira M30 based on the R31 Skyline GTS-R. A modified RB20DE head was bolted on to the RB30E block. It delivered 177 kW (240 PS) @ 7000 rpm and 294 N·m (30.0 kgf·m) @ 4800 rpm.
RB30DET
RB30DET - R31 RB30E block, R32 RB25DE head.
RB30DET - R31 RB30E block, R32 RB25DE head.
Nissan did not produce this engine, but it refers to a turbocharged engine featuring an RB30E block with a twin-cam head conversion. Common hybrid in Australasia using a RB30E bottom end mated to a RB25DE,RB25DET or RB26DETT cylinder head and turbo (RB20DE and DET heads are not used as the bores are different in size; RB30 86.0mm RB20 78.0mm). The RB25DE cylinder head from the R32 Skyline, A31 Cefiro or C33 Laurel can be used, and fits perfectly on (although better valve springs are required to prevent valve float when running any more than stock boost). The RB25DET (from the R33 Skyline or C34 Laurel or Stagea) head is also used, however an external oil feed must be fabricated for the variable cam timing on the RB25DET, and the galleries at the front of the engine do not line up. The variable cam timing may be disconnected altogether.
The fitment of a twin cam head from any of these engines onto a standard compression RB30E bottom end gives an ideal compression ratio for a mild to moderately modified street turbo engine, making the conversion popular amongst those who would otherwise convert their RB30E to a high compression RB30ET using original ET bolt on externals.
Although it has a larger displacement than the RB26DETT, maximum possible horsepower is less, as the RB30 block lacks the RB26 block's internal cast-in bracing, and consequently cannot rev as high due to harmonic issues at ~7500 rpm. To compensate, the RB30DET produces more torque at lower revs. There is also an 'RB30DETT' kit manufactured by OS Giken of Japan, which bolts an extension on top of the RB26 engine block, and fits liners, to give an 86 mm bore x 86 mm stroke. It is available as an assembled short block, containing billet chrome-molybdenum crank, billet chrome-molybdenum H-beam connecting rods, forged pistons, and costs ¥1,500,000.
